It sounds like sorcery, but electricians already use tools with similar technology so they can quickly assess if a wire is carrying power without having to connect a multimeter. Ten One Design has not only improved the sensitivity with the non-contact voltage sensor it’s incorporated into Stella, the company has also worked to minimize the power consumption of the built-in LED flashlight so that it should run for well over a decade on its integrated battery. You’ll have long replaced your laptop by the time it stops working.
The $35 Stella will be available in two versions for Mac and PC laptops, but the Mac version includes an additional upgrade to the hardware that Apple ships. Ten One Design has included a slide-out clip so that when the Stella is connected to your MacBook’s power brick, you have a better way to wind and secure its braided power cord. It’s a small improvement, but one that MacBook users might actually be even more excited for than Stella’s automatic flashlight.
According to gizmodo